Science never stops

I have written before about how climate change deniers never retract an argument, no matter how thoroughly debunked and discredited it has become. By contrast, climate scientists admit their mistakes, which can make them seem less credible than the hyper-confident advocates of inaction.

In their new book, Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming, Naomi Oreskes and Erik Conway bring up a related issue:

Doubt-mongering also works because we think science is about facts – cold, hard, definite facts. If someone tells us that things are uncertain, we think that means that the science is muddled. This is a mistake. There are always uncertainties in any live science, because science is a process of discovery. Scientists do not sit still once a question is answered; they immediately formulate the next one. If you ask them what they are doing, they won’t tell you about the work they finished last week or last year, and certainly not what they did last decade. They will tell you about the new and uncertain things they are working on now. Yes, we know that smoking causes cancer, but we still don’t fully understand the mechanism by which that happens. Yes, we know that smokers die early, but if a particular smoker dies early, we may not be able to say with certainty how much smoking contributed to that early death. And so on.

There is much that is laudable about the way scientists communicate their ideas – cautiously, with reference to evidence, and so on – but it is also easy to see how public relations people looking to discredit scientific conclusions can use quirks in scientific communication to their advantage.

Thankfully, it does seem that climate scientists are becoming more savvy about media relations, and are increasingly making the point that choosing to do nothing while even more evidence is accumulated is a reckless strategy. We cannot wait for all aspects of the science to be settled; rather, we need to start taking precautionary action now, before the worst impacts of climate change become measurable.

A presentation based off of her recent book, Merchants of Doubt: How a Handful of Scientists Obscure the Truth about Climate Change. Naomi Oreskes, author and professor of history and science studies, University of California, San Diego.

On p.116 of the hardcover edition of the Oreskes book, there is a nice example of a scientist being quick to bring forward new information, even though it somewhat undermined an argument they had made previously.

In 1976, Sherry Rowland discovered that chlorine nitrate survived longer in the atmosphere than previously understood. This reduced the amount of ozone depletion their model estimated would be created by CFCs by 20-30%. Despite how Rowland had already advocated limiting CFC production for the sake of ozone, he was quick to announce the new information. The National Academy of Sciences then insisted on delaying two forthcoming reports, so as to be able to fully and accurately include the new information in their assessment.

There are a couple of tell-tale signs of this ‘Potemkin heresy’ that mark it out as not quite kosher. First, for the heretic who has a coherent alternative to the orthodoxy, it is very unlikely that this alternative will be in line with the thoughts of all the other outsiders. True heresy is actually very lonely. If alternatively, the ‘heresy’ consists of thinking that every idea that pops up is worthy of serious consideration, they are simply throwing away the concept of science as a filter that can actually take us closer to reality. If every idea must now and forever, be considered anew whenever someone brings it up, no progress is possible at all. Science works because it can use observations from the real world to move on from unsupported or disproven ideas. All ideas are in principle challengeable, but in practice, unless there is new information, old issues get resolved and put aside. The seriousness of a new ‘heresy’ then, can be measured in how much shrift is given to the crackpots. As Sagan said, one should always keep an open mind, but not one that is so open that your brains drop out.

At the heart of all IPCC projections are “emission scenarios:” low-, mid-, and high-range estimates for future carbon emissions. From these “what if” estimates flow projections for temperature, sea-rise, and more.

Projection: In 2001, the IPCC offered a range of emissions trends, from a best-case scenario of just 8 billion tons of carbon released each year to a worst-case scenario of 30 billion tons produced annually by 2100.

Reality: In 2011, Global emissions totaled 31.6 billion tons of carbon, according to the International Energy Agency, exceeding IPCC’s worst-case scenario 88 years ahead of schedule.

…

Projection: In 1995, IPCC projected “little change in the extent of the Greenland and Antarctic ice sheets… over the next 50-100 years.” In 2007 IPCC embraced a drastic revision: “New data… show[s] that losses from the ice sheets of Greenland and Antarctica have very likely contributed to sea level rise over 1993 to 2003.”

Reality: Today, ice loss in Greenland and Antarctica is trending at least 100 years ahead of projections compared to IPCC’s first three reports.

Why the miss? “After 2001, we began to realize there were complex dynamics at work – ice cracks, lubrication and sliding of ice sheets,” that were melting ice sheets quicker, said IPCC scientist Kevin Trenberth. New feedbacks unknown to past IPCC authors have also been found. A 2012 study, for example, showed that the reflectivity of Greenland’s ice sheet is decreasing, causing ice to absorb more heat, likely escalating melting.